| 摘要 |
894,669. Rotary pumps. HOBOURNEATON MANUFACTURING CO. Ltd. Nov. 30, 1960 [Dec. 22, 1959], No. 41130/60. Class 110 (2). A rotary pump of the roller-vane type comprises a rotor 14, Fig. 2, mounted on a driving- shaft 20 for rotation eccentrically in a cam-ring 13 disposed in a recess 19 of the housing part 15 of a two-part housing 15, 16 and formed with a number of angularly-spaced transverse slots 63, Fig. 6, each co-operable with a roller 64. The trailing wall 67 of each slot is formed with a pair of blind bore recesses 75, 76, Fig. 8, opening from opposite faces of the rotor and co-operating with arcuate recesses 32, 33 in the housing part 15 and corresponding arcuate recesses 32a, 33a in the housing part 16 to facilitate the flow of pumping fluid into the pumping spaces adjacent the rollers and with arcuate recesses 34, 35, in the housing part 15 and corresponding arcuate recesses 34a, 35a in the housing part 16 to facilitate the discharge of the pumped fluid, to reduce noise and the mechanical bumping of the rollers against the rotor and the cam-ring. When the rollers, see 64a, 64f, Fig. 6, on either side of a sealing portion 57 of the cam-ring separating the intake sector 58 of the pump from the discharge sector 59, are in retracted position the recesses 75, 76 permit the flow of pressure fluid to behind the rollers to hold the rollers in fluid balance. A by-pass valve (not shown) may be fitted in a chamber 48, Fig. 4, interconnecting the recesses 34a, 35a with the recesses 32a, 33a. The chamber 48 is also connected to an intake port 43 and the pump discharge port 46.
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